/*	$NetBSD: strerror_r.c,v 1.5 2020/03/25 16:15:41 kre Exp $	*/

/*
 * Copyright (c) 1988 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/cdefs.h>
__RCSID("$NetBSD: strerror_r.c,v 1.5 2020/03/25 16:15:41 kre Exp $");

#include "namespace.h"
#include <assert.h>
#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <stdio.h>	/* for sys_nerr on FreeBSD */
#ifdef NLS
#include <stdlib.h>
#include <limits.h>
#include <nl_types.h>
#define __SETLOCALE_SOURCE__
#include <locale.h>
#include "setlocale_local.h"
#endif

#include "extern.h"

__weak_alias(strerror_r, _strerror_r)

#define	UPREFIX	"Unknown error: %d"

#ifdef NLS
static char **cachederrmsg;
static locale_t cachedloc;

static void
cachelocale(locale_t loc)
{
	int i;
	nl_catd catd;

	if (cachederrmsg != NULL) {
		for (i = 0; i <= sys_nerr; i++)
			free(cachederrmsg[i]);
	} else {
		cachederrmsg = calloc(sys_nerr + 1, sizeof(*cachederrmsg));
		if (cachederrmsg == NULL)
			return;
	}

	catd = catopen_l("libc", NL_CAT_LOCALE, loc);

	for (i = 0; i < sys_nerr; i++) {
		cachederrmsg[i] = strdup(catgets(catd, 1, i, sys_errlist[i]));
		if (cachederrmsg[i] == NULL)
			goto err;
	}
	cachederrmsg[i] = strdup(catgets(catd, 1, 0xffff, UPREFIX));
	if (cachederrmsg[i++] == NULL)
		goto err;
	cachedloc = loc;
	catclose(catd);
	return;
err:
	catclose(catd);
	while (i > 0)
		free(cachederrmsg[--i]);
	free(cachederrmsg);
	cachederrmsg = NULL;
}

static char *
nlserror(unsigned int num, unsigned int nerr, locale_t loc)
{
	char *errmsg;
	nl_catd catd = catopen_l("libc", NL_CAT_LOCALE, loc);

	if (num < nerr)
		errmsg = catgets(catd, 1, num, sys_errlist[num]);
	else
		errmsg = catgets(catd, 1, 0xffff, UPREFIX);

	catclose(catd);
	return errmsg;
}
#endif

int
_strerror_lr(int num, char *buf, size_t buflen, locale_t loc)
{
	unsigned int errnum = num, nerr = sys_nerr;
	int retval = 0;
	size_t slen;
	char *errbuf;
	int saved_errno = errno;
#ifdef NLS
	if (loc != cachedloc || cachederrmsg == NULL)
		cachelocale(loc);

	if (cachederrmsg != NULL)
		errbuf = cachederrmsg[errnum < nerr ? errnum : nerr];
	else
		errbuf = nlserror(errnum, nerr, loc);
#else
		errbuf = errnum < nerr ? sys_errlist[errnum] : UPREFIX;
#endif
	_DIAGASSERT(buf != NULL);

	if (errnum < nerr)
		slen = strlcpy(buf, errbuf, buflen); 
	else {
#ifdef NLS
		slen = snprintf_l(buf, buflen, loc, fmtcheck(errbuf, UPREFIX),
		    num);
#else
		slen = snprintf(buf, buflen, fmtcheck(errbuf, UPREFIX), num);
#endif
		retval = EINVAL;
	}

	if (slen >= buflen)
		retval = ERANGE;

	errno = saved_errno;

	return retval;
}

int
strerror_r(int num, char *buf, size_t buflen)
{
#ifdef NLS
	return _strerror_lr(num, buf, buflen, _current_locale());
#else
	return _strerror_lr(num, buf, buflen, NULL);
#endif
}